Apparatus for drilling core samples



July 4,1967 R. K. DYER APPARATUS FOR DRILLING CORE SAMPLES Filed July lO, 1964 DYER ROBERT K. lay/ho A TTOR NE Y:

United States Patent Office 3,329,220y Patented July 4, 1967 3,329,220 APPARATUS FOR DRILLING CORE SAMPLES Robert K. Dyer, Longview, Tex., assigner, by mesne assignments, to Sinclair Research, Inc., New York, N.Y., a corporation of Delaware Filed July 10, 1964, Ser. No. 381,820 14 Claims. (Cl. 175-94) This invention relates to an improved apparatus for obtaining a subterranean core in or near its original geological condition. The apparatus provides a coreretaining barrel supported by a hollow shaft which during the course of the drilling and core recovery is rotated, and reciprocated by the application of fluid pressure. During the drilling, drilling mud can be circulated down through the hollow shaft and the core-retaining barrel and upwardly around the outside of the shaft.

In this invention the core-retaining hollow barrel is usually cylindrical. A motor, e.g., electric or, preferably, a fluid current motor provides the mechanical energy for drilling, and air or other fluid pressure is used to extend and retract the core barrel, preferably automatically. Another motor, e.g., electric or fluid current, can be employed along with a pump for circulation of the drilling mud and this circulation system can be provided with a filter for removal of drill cuttings. In a preferred embodiment of this invention, the reciprocation means are supported by the shaft and comprise a cylinder which encloses a piston affixed to the outside of the shaft which divides the cylinder into two chambers. Air or other fluid under pressure is forced into the upper chamber for the downward portion of the reciprocation cycle and into the lower chamber for the retraction portion of the reciprocation cycle. The entry of fluid under pressure and withdrawal of air vis-a-vis the two chambers employs tubes leading to the chambers from a mechanism which preferably selects the tube for each function in response to the position of the shaft. In this way the reciprocation of the shaft and core barrel may be automatically controlled.

The hollowness of the shaft permits drilling mud to be pumped downward through the shaft to the core barrel and then to the -cutting zone during operation of the core sampling device. Mud, containing cutting, etc., can pass up around the outside of the shaft to a pump for recirculation but travel to the pump in a preferred ernbodiment is interrupted by a filter, preferably an elongated cylindrical filter, the interior of which acts as a reservoir for the filtered drilling mud. The apparatus `usually includes a pipe or casing which can surround the shaft and barrel and isolate the zone to be cored. The casing or pipe can include a packing section of more-or-less conventional design and serves as a conduit to guide upwardly-flowing drilling mud to the filter and pump. A significant advantage of the apparatus of this invention is its ability to use a fluid current motor to operate the drilling mud pump and also a fluid current motor lto rotate the shaft and drilling bit. Thus, the line supplying compressed fluid, usually air, for reciprocation of the drilling bit can be used to supply all the motive power `needed for the core sample drilling.

The invention will be better understood by reference to the accompanying drawing which shows, partly in section, an embodiment of the novel apparatus of this invention, broken into the lower section in FIGURE 1A and the upper section FIGURE 1B.

The apparatus comprises a hollow cylindrical pipe or casing having the metallic anchor section 11 which is provided with the drillable anchor shoe 13. Above the anchor is the formation packer section 15 of more-orless conventional design which holds the casing substantially fixed with relation to the walls of the well or other subterranean formation. The upper section 18 of the hollow cylindrical pipe extends upwardly from the packing more-or-less to the surface of the earth, not shown.

The interior of the upper pipe section 18 is provided with the more-or-less air-tight sealing partition 20 which divides the apparatus into the upper or air chamber 22 and lower or mud chamber 25. The sealing partition 20 has the exhaust hole 27 which preferably contains the vent tube 30, as well as the air supply tube 33 which also may reach to the surface of the earth or beyond. Air supply tube 33 leads to the fluid current motor and pump combination 36 by means of connection 39, to fluid pressure flow regulator 42 by line 44 and to second fluid current motor 46. Motors 36 and/ or 46 may, where desired, be replaced by electric motors and suitable wiring for the same may be supplied. In this eventuality the line 33 still leads, by way of line 44, to the flow director 42. Motors 36 and 46 and flow director 42 are affixed to the interior of the tube portion 18.

The core barrel 50 is a hollow cylindrical member which may be of conventional design enclosing the chamber 52 and provided at its lower edge with the circular drilling member 53. As shown, this member provides a passageway 55 of slightly smaller cross-section than the chamber 52. Generally, this member is made of a hard abrasive material or a hard abrasive such as diamond dust may be embedded in its surface. The core barrel Si) is supported by the hollow shaft S7 having the central passageway 60. The shaft 57 bears the cylinder 63 and the collar 66, preferably in the portion below the packer section 15. Cylinder 63 generally will be fixed to pipe section 11, by any suitable means (not shown). Collar 66 acts like a piston within the cylinder 63 dividing the cylinder `into upper chamber 68 and lower chamber 70.

An upper portion of the shaft S7, preferably above the packer section 15 has means for being driven by a rotating driving means. For example, the shaft 57 may be provided with a plurality of splines 72 which mesh with the gear 75. The gear 75 may be affixed to shaft 77 which in turn is driven in rotary fashion by motor 46. Thus, motor 46 may transmit power by means of elements 77, 7S, 72, 57 and 50 to rotate the head 53 for drilling through the shoe 13 and into the earth, not shown.

The downward force for driving head 53 and core barrel 50 into the earth is supplied by forcing air or other fluid from conduit 33 into the chamber 68 above the piston collar 66, by means of line 80 which connects chamber 68 to flow director 42. For purposes of clairity the midsection of this line 80 is not shown. Line 80` and flow director 42, of course, transmit pressure from connection 44 and line 33. Exhaust fluid from chamber 70 passes to flow director 42 by way of line S1, the mid-section of which also is not shown. The upward portion of the reciprocation cycle is accomplished by applying the fluid pressure from line 33 to chamber 70` through line 81, while allowing line 80 to carry exhaust fluid from chamber 68 back to the flow director 42. Flow director 42 may operate by more-or-less conventional means to direct the fluid in line 33 and connection 44 to either line 80 or line 81 using, for example, a slide valve arrangement.

Shaft 57 is revolvably suspended at its upper end from fitting 82 which is, in turn, suspended from the hollow double turbe expandable or telescoping connection indicated generally Ias `84. This connection, as can be seen, comprises the v-movable outer tube 86 and the stationary inner tube 88 which is afllxed to motor and pump unit 36. It can readily be seen that the fitting 82 and connection 84 provides an upper extension 90 of passageway 60. These passageways 60 and 90 receive drilling mud from the motor and pump combination 36 and deliver the mud, preferably by way of space in the chambe-r 52, to the drilling head 53. Motor and pump combination 36 receives the mud, in turn, from connection 93 and reservoir 96, contained within the cylindrical filter element 99. This element is generally a relatively coarse rigid material, for example a porous ceramic, or stiff wire mesh which may be open at the top, as shown, or covered. In operation of the device, drilling mud leaving the chamber 52 through the opening in head 55 passes into the formation being drilled and then back into the chamber 25, carrying the drill cuttings, and passes up and around core -barrel 50', cylinder 63, shaft 57, drive elements 75, 72 and 77, fitting 82, connection 84, motor 46, control member 42 and motor 36` to an area along the filter 99 through which it may be drawn, without the cuttings, `for recycle to the passageways 90 and 60.

`Connection 84, in particular, the movable extern-al tube 86, is provided with contact lugs. Lower lug 101 is preferably below the flow director 42 while upper lug 103 is above 42. The lugs are u-sually spaced apart by a distance equal to the desired `vertical travel of the ycore barrel 50.

As air continues to enter chamber 68, piston collar 66 is `forced downwardly. Downward movement of the collar 66 brings about downward movement of shaft 57, fitting 82, outer tube 86 and lugs 101 and 103. At the desired lowermost limit of downward movement, lug 103 contacts switch 105 on fioW director 42 causing downward air to be diverted from line 80 to line 81 which leads to chamber 70 within the cylinder 63. This forcing of air into chamber 70 results in upward movement of outer tube 86, fitting 82, shaft 57 and core barrel 50, which at this time containsv a core sample. This automatic retraction movement is ended by the lower lug 101 contacting the switch 105. Flow regulator 42 may be provided with exhaust line 107 while motor 46 is provided with air exhaust line 109 and motor-pump combination 36 is provided with air exhaust line 111. These exhaust lines may be connected to each other and to the vent line 30 i-f desired; otherwise exhaust air may be allowed to bubble upward through the mud, which may be a zero water loss mud.

The apparatus of the invention may be installed in a formation to be sampled by procedures which are readily apparent. When sampling is corripleted the cylinder and its contained elements may be lifted from the well and the core retrieved.

I claim:

1. An apparatus for drilling core samples comprising an elongated tubular housing, packing means disposed at an intermediate position along the exterior of said housing for sealingly engaging the wall of a well into which the apparatus can be inserted, a core-retaining hollow drill barrel disposed in the lower portion of said housing, said barrel being anchored to and in open communication with a hollow shaft above said barrel, means for reciprocating said shaft and lba-rrel by -fiuid pressure, -means for rotating said shaft and barrel, and means for cyclically recirculating a fluid mud downwardly through said shaft and barrel and upwardly around the outside of said shaft.

2. The apparatus of claim 1 wherein said hollow shaft is provided on its outside with a spline, said means to rotate said shaft and barrel is a fluid current motor, and said spline is in operative engagement with said fluid current motor to rotate said shaft and barrel.

3. The apparatus of claim 1 in which the means for reciprocating said barrel comprises a fixed cylinder supported around the 'outside of said shaft and 4a piston fixed to the outside 'of said shaft dividing the said cylinder into an upper and a lower chamber, each of said chambers having a line for the introduction of pressure uid into the chamber.

4. The apparatus of claim 3 in which said lines for introduction of fiuid pressure are connected to a means for directing said fiuid pressure selectively into one of 4 said lines while pressure is relieved from the other of said lines.

5. The apparatus of claim 4 in which said selective means is 'operated by members afiixed to said shaft.

6. An apparatus for drilling core samples comprising a core-retaining hollow cylindrical barrel supported by a hollow shaft, said shaft having means for reciprocating said shaft and barrel by fluid pressure, means for rotating said shaft and barrel and means for cyclically circulating drilling mud downwardly through said shaft and barrel and upwardly between the outside of the shaft and a hollow pipe surrounding said shaft including a cylindrical filter and a pump which draws mud from the exterior of said filter through the filter to the interior of said filter, said filter being located above said pump.

7. The apparatus 'of claim 6` in which said pump is operated by a fluid current motor.

8. An apparatus for drilling core samples comprising an elongated tubular housing having a drillable closed lower end, packing frneans disposed at an intermediate position along the exterior of said housing for sealingly engaging the wall of a well into which said apparatus can be inserted, ya core-retaining hollow drill barrel disposed in the lower portion of said housing, said barrel being anchored to and in open communication with a hollow shaft above said barrel, means for reciprocating said shaft and barrel by fiuid pressure, means for rotating said shaft and barrel, and means for cyclically recirculating a fluid mud downwardly through said shaft and barrel and upwardly around the outside of said shaft.

9. The apparatus of claim 8 in which the exterior of said shaft carries a plurality of elongated splines for providing engagement with said rotating means during reciprocation of said shaft and Ibarrel.

10. An apparatus for drilling core samples comprising an elongated tubular housing having a drillable closed lower end, packing means disposed at an intermediate position along the exterior of said housing for sealingly engaging the wall of a well into which the apparatus can be inserted, -a core-retaining hollow drill barrel disposed in the lower portion of said housing, said barrel being anchored to Vand in open communication with la first hollow shaft above said barrel, means for reciprocating said first shaft and barrel by fluid pressure, means -for rotating said first shaft and barrel, and means for cyclically recirculating a fiuid mud downwardly through said first shaft and barrel and upwardly around the outside of said first shaft including pump means and a second hollow shaft, the first hollow shaft engaging said second hollow shaft, said second shaft telescopingly engaging the outlet of said pump means for circulating said fiuid.

11. The apparatus of claim 10 in which the means for cyclically circulating drilling mud includes a cylindrical filter located above a pump which draws mud from the exterior of said filter, through the filter to the interior yof said filter.

12. The apparatus of claim 11 in which the means for reciprocating said barrel comprises a fixed cylinder supported around the outside 'of said first shaft and la piston fixedto the outside of said first shaft dividing the said cylinder into an upper and a lower chamber, each `of said chambers having a line for the introduction of pressure fluid into the chamber.

13. The apparatus of claim 12 in which said lines for introduction of fluid pressure are connected to a Imeans for directing said fluid pressure selectively into one of said lines while pressure is relieved from the other of said lines.

14. The apparatus of claim 13 in which the said selective means is operated by members affixed to said second shaft.

(References on following page) Gould 175--94 Carey 175-78 Danner 175-78 X Fisher 175--92 Harris 175--20 6 Jones et al 175-307 X Matthews 175-307 Zeni 175-94 -De-mo 175-135 Lincoln 175-135 CHARLES E. OCON'NELL, Primary Examiner. R. E. FAVREAU, Assistant Examiner. 

1. AN APPARATUS FOR DRILLING CORE SAMPLES COMPRISING AN ELONGATED TUBULAR HOUSING, PACKING MEANS DISPOSED AT AN INTERMEDIATE POSITION ALONG THE EXTERIOR OF SAID HOUSING FOR SEALINGLY ENGAGING THE WALL OF A WELL INTO WHICH THE APPARATUS CAN BE INSERTED, A CORE-RETAINING HOLLOW DRILL BARREL DISPOSED IN THE LOWER PORTION OF SAID HOUSING, SAID BARREL BEING ANCHORED TO AND IN OPEN COMMUNICATION WITH A HOLLOW SHAFT ABOVE SAID BARREL, MEANS FOR RECIPROCATING SAID SHAFT AND BARREL BY FLUID PRESSURE, MEANS FOR ROTATING SAID SHAFT AND BARREL, AND MEANS FOR CYCLICALLY RECIRCULATING A FLUID MUD DOWNWARDLY THROUGH SAID SHAFT AND BARREL AND UPWARDLY AROUNG THE OUTSIDE OF SAID SHAFT. 